Monday, March 12, 2012

It’s Sunday morning, and I’m looking at a swarm of goldfinches and common redpolls – perhaps 50 or 60 – which are energetically competing for access to one particular tube feeder and a platform feeder outside our home. And while I’m delighted, I’m also worried – has this high number of birds now exceeded some healthy threshold and our supplemental feeding now transformed from something we thought was “good” to something “bad”?

I’ve always ascribed to “moderation in all things,” but how does one define moderation? When does one cross the invisible line from moderation into excess? When does too much helping become harming?

This notion of a middle-way, a balanced life, suffuses nearly everything all of us do. How much is too much when we eat? When are we speaking too loud, or too long, or too forcefully? When are we paying too much attention to one thing and not enough to another? When does too much work make us a workaholic? When is one more pill an overdose?

On a social scale: When do visitors stay too long? How many fishing boats on a lake, or hikers on a trail, or people at a campground, make it too crowded? How many kids are too many in a classroom?

The examples are literally endless, but to bring the question back to feeding wildlife, how much feeding is “just right”? If one tube feeder is good for the birds, are 10 feeders? One hundred feeders? Likewise, if one can of corn attracts two deer, what about a five-gallon pail that attracts six deer? Why not a wheelbarrow then, or pick-up truck load?

When do we go from helping a wildlife species, or many species, to actually creating potential harm? Dr. Doolittle was an entertaining Walt Disney character, but turning large numbers of wild animals into semi-domesticated pets is not the middle way.

I don’t have any absolute answers to this question. Based on the best science and observation that we can bring to bear, there’s an art and a wisdom needed in finding the middle way. And the way is dynamic – it changes as seasons and behaviors change.

So what do we need to be considering? Well, there’s a long list. For one, too many animals feeding in one space creates a much higher risk of disease. Over the years, we’ve had salmonella poisoning occur at our feeders at least twice in the late winter/early spring, and whether that was because we were feeding too many birds, or we hadn’t cleaned our feeders sufficiently, or birds were arriving from elsewhere already with salmonella is something we’ll never know. But we do know that hordes of animals – birds or mammals – feeding from the same general plate greatly increases the risk of transmitting disease.

Two, crowding increases stress. However, how stress plays out is highly variable, and we only see what is in view of our feeders. All animals have breeding territories that vary in size according to how well their needs are met not only for food, but also for cover, for breeding/nesting/denning, for rearing of young, et al. So, when we bring many individuals together within a territorial pair’s domain, what are the consequences? What is the difference in winter when territories are less restrictive and animals are more social? How about spring migration?

All animals also have a home range, an area in which they may wander in search of food or other needs. When we change their normal travel and feeding behaviors by dint of providing a five-star restaurant in our yards, what are the consequences? The deer that no longer yard up in the winter or no longer travel their normal feeding paths throughout the year are now concentrated in one area. Habituation often becomes an issue – if animals become too familiar or comfortable with the presence of humans they may fail to exercise their natural instinctive behaviors, such as response to danger.

All animals also have adaptive behaviors that have been honed over thousands of generations to “fit” all the needs of their life histories throughout all the variations of the seasons. How are we altering essential behaviors if we feed too much? When does our home become the equivalent of a feedlot rather than merely a supplemental source of food? When are we creating a dependency, particularly for juveniles who need to learn how to fend for themselves?

We all get great enjoyment from watching wildlife, but along with the privilege of interacting with wild animals comes a responsibility to ensure their health is maintained.

I should add that we also have responsibility to our human neighbors. When we entice a herd of deer into our yard, the deer are also very likely to browse every tree, shrub, and wildflower in the general vicinity. When we entice 50 geese to our shoreline, their predilection for eating grass spills over onto other peoples’ properties, as does their waste, both in the water and in yards.

So, now that swarms of redpolls are arriving at people’s feeders – I’m getting phone calls from people saying they have hundreds of birds now at their feeders – is it the “right” thing to do to vastly increase our seed output to feed them all, or should we continue feeding modestly so that they don’t concentrate at our feeders for weeks thereby increasing the risk of disease?

I’m opening this up as a discussion, and I’d like to hear from you – please e-mail.

Chickadee Tree ID and Caterpillar Choices

We humans aren’t the only ones that can learn to identify trees. According to researchers at UC Irvine and Wesleyan University, birds learn to identify trees, too. In this particular study, the researchers showed that chickadees and other birds can learn to zero in on the species of tree as much as on the characteristics of their insect prey.

For the insects – caterpillars in this case – the study results also demonstrate that dining on the trees that are most nutritious for them, such as the black cherry, can increase their chances by 90 percent of being devoured by a discerning bird. Researchers discovered that the healthiest tree species harbor the greatest number of caterpillars, thereby offering the easiest targets for birds, and the birds learn this.

From the caterpillar’s standpoint, they’re between a rock and a hard place. The research illustrated a stark choice for them between gaining strength through a good diet utilizing the healthiest trees (but thus being more vulnerable to predators), or remaining weaker and hungrier but much safer by utilizing poorer quality trees.

One of the researchers summarized the study this way: "If a caterpillar could feed on nutritious, high-quality tree species and be left alone, this would be the best of all worlds. Instead, it's faced with a trade-off. Overall, it appears that it's better to feed on poor-quality tree species . . . than to be on a nutritious plant with many others."

Loon Tracking

It’s March! Loons will soon be tracking their way north, hop-skipping-jumping their way here as the weather dictates. But where are they now? Most likely in the Gulf of Mexico below the Florida panhandle. Kay Rhyner sent me on e-mail on 2/26 that read: “We visited Marco Island, Florida last week. We were at my brother's home along one of the canals. One morning a loon was out there diving and fishing. I, needless to say, was very excited and wondered if it was "our" loon from Yawkey Lake in Hazelhurst. Then he came up with a very large fish and seemed to be kind of struggling with it and then a pelican dove in and snatched the fish right out of the loon's beak.”

Kay was wondering about the loons from Yawkey Lake, and, of course, there is no way to know where they are right now. But a few of you do have a way! Loons on Trout, Star, Island, and Escanaba Lake were all outfitted with satellite transmitters last summer, and can be followed in their migration on the USGS Common Loon Migration Study site at:www.umesc.usgs.gov/terrestrial/migratory_birds/loons/migrations.html

Sightings

I had several people contact me saying they had seen a small bear in the last few weeks, and were wondering what could be the explanation. My speculation is that they saw a yearling bear (last year's cub). This year's cubs would be very small yet, and probably still nursing. The young are typically born in late January and early February, and don't even open their eyes for 25 days, so a new cub "should" be out of the question (never say never, though). At one year of age, a yearling will weigh from 40-75 pounds, so perhaps they saw one at the very lowest end of that weight scale. Females breed every two years, so the yearlings stay in the den with the mother, though they may have nearby individual dens.

As to why a bear would be running around in February, something had to have disturbed the den. On occasion, loggers drop trees inadvertently on dens, or just the commotion of logging scares them out. One way or another, the yearlings will be hungry, and I suspect they may spend a lot of time near bird and deer feeders.

Celestial Events

For planet watching in March, at dusk look for brilliant Venus in the west, and Jupiter, only slightly less brilliant, in the southwest. Before dawn, Mars will be low in the northwest, and Saturn will rise high in the south by 3 a.m.

Our average high temperature reaches 32°F on March 6. The full moon shines bright on March 7. Called the “Crust on the Snow Moon” by the Ojibwe, the name denotes very tough walking conditions for deer, which will constantly break through the crust, but fabulous conditions for lightweight creatures like snowshoe hares that can now stay on top of the crust.

We hit 11.5 hours of sunlight on 3/8, well on our way to the Vernal equinox on 3/20.

On 3/15, look for Venus just 3 degrees above Jupiter.

American Marten Grant to Mercer School

Congratulations to Zach Wilson and the North Lakeland Discovery Center! Coached by Zach, students in Mercer are participating in Wisconsin’s American marten management plan by helping researchers trap and track the animals. The students have helped place radio collars on 12 martens near Mercer and regularly perform radio-telemetry work to log the animals' movements. The Mercer project is among 12 finalists in a Samsung project selected from more than 1,500 applicants. Judges will select four grand-prize winners, and online voters will select a fifth. All winners will receive equipment for their school. To view the Mercer school marten video and support their contest entry, visit https://pages.samsung.com/us/sft/video/index.jsp. Voting ends at midnight March 12.

The Great Backyard Bird Count (GBBC) is an annual 4-day event sponsored by Audubon and the Cornell Lab of Ornithology that engages birdwatchers of all ages across North America. Anyone can participate, from beginners to experts. You can count for as little as 15 minutes on a single day, or as long as you like each day of the event. It's free and really quite easy. To participate, go to http://www.birdsource.org/gbbc/howto.html

This year's count runs from Friday, February 17, through Monday, February 20. It's as simple as counting birds in your backyard, tallying the highest number of birds of each species seen together at once, and filling out an online checklist on the GBBC website. As the weekend progresses, visit the website http://www.birdsource.org/gbbc/ to check out results.

Snowy Owl near Bergland, MI

Mercer-based professional photographer Jeff Richter called me a week ago to join him in a photographic chase of a snowy owl that had been seen in the Bergland, MI, area. Snowies like open lands that mimic their home tundra, and this area has a good number of large open fields. Jeff had been photographing the bird for several days and knew its general whereabouts, but like all wildlife, it wasn’t tethered to a spot. So, we slowly drove a number of local roads until Jeff finally spotted the owl well out in a field on a fence post. It then kindly took off and flew to the top of a conifer next to a road where we could get close enough to photograph it.

My little camera could do little justice to the beauty of the owl, but Jeff’s professional cameras will certainly have captured some great images. Jeff is one of the few photographers left who still shoots film, so I can’t share any of his images, but here’s one of mine.

Few snowies have been reported in the northwoods in the past few weeks, but are still being seen in southern Wisconsin. See http://www.tinyurl.com/snowyowlWIthruJan for a map of all the sightings in Wisconsin this winter.

Eagles in the Snow

Robert Eady at the Conserve School in Land O’Lakes sent me a photo of two eagles splayed side-by-side in the snow (see photo by Jeff Rennicke) and wanted to know what I thought might be going on.

I e-mailed Ron Eckstein for his more authoritative thoughts. Ron is a retired DNR wildlife biologist who has banded several thousand eagles. Here’s what he wrote: “It is a territorial battle between two adult eagles. In Vilas County we usually see these fights in February through early April. I can't tell sex from the photo (females are larger). It appears the eagle on the left is a full adult (at least 5 years old) and the eagle on the right is likely a 4 year old (because of the dark feathers still present above and to the rear of the eye . . . the last of their immature feathers occur around the eye . . . and because the bill is not yet uniformly yellow). It is possible that an adult from a pair died and these eagles are fighting to see who is the new mate. Likewise, it is possible that the subadult and another adult are trying to set up a new territory close to one of the existing territories.”

Western Great Lakes Region Owl 2011 Survey

The Western Great Lakes Region Owl Survey was initiated in 2005 to understand the distribution and abundance of owl species in the region, to determine trends in their abundance, and to determine if the owls are associated with specific habitats.

Last spring 63 volunteers surveyed 80 routes throughout Wisconsin and detected 177 owls of five species. The overall mean number of owls per route was the highest in survey history. Barred owl detections were near record high, while great horned owls rebounded after a poor showing the previous year. Northern saw-whet owls, however, fell after a spike in detections in 2010. The top three owl species combined for Minnesota and Wisconsin were barred owl, great Horned Owl, and northern saw-whet owl, respectively.

The owl survey period went from April 1 to April 15, each survey starting at least one half-hour after sunset.

Analysis of surveys such as this has its riddles. It’s certainly possible the owl population truly increased or decreased in number, which could be related to a decrease in available habitat, more abundant prey populations, or other variables. However, another possibility is not a change in numbers but a change in detectability. Hearing owls may be affected by the observer’s skill, wind, or other external noise sources, such as frogs, traffic, etc. An owl’s calling activity is also affected by the time of year, the time of night, various weather conditions, and a host of other factors. Unfortunately, many of these factors are poorly understood, so one needs to really look at long-term data to get a picture of what’s really going on, and this survey at only seven years old is too young to do that. Over time though, the data should suggest trends, and thus help biologists to know what’s taking place in the world of owls.

Sightings

Roger Belongia on the Turtle-Flambeau Flowage reports that he has around 35 common redpolls, seven female and one male pine grosbeaks, and for the first year in the last 28 years he has four starlings spending the winter in his yard.

On 2/9, Sharon Lintereur in Lake Tomahawk saw a bobcat at 5 a.m. just outside of Lake Tom chewing on a dead deer. She stopped and tried to get a picture, but it ran off. Sharon also notes that they have an abundance of redpolls and woodpeckers including downy, hairy, pileated, and red-bellied this year.

Northern shrike sightings continue to be on the rise. On 02/07/12 Sue DeFrancisco in Minocqua identified a northern shrike hawking their feeders almost all day, but with apparently no luck. On 2/6, Phil and Nancy Williams in Winchester also had a shrike watching their bird feeders, while Mike and Carol Beno in Presque Isle had the best shrike story: “The first week in January, a northern shrike came to our bird feeders in late morning. It sat in the snow beneath the feeders, likely watching for one of the voles that tunnel in the snow amid the fallen seed. It spent a lot of time there before flying off, empty handed. Later that week the shrike returned. It flew in from the woods, grabbed a chickadee feeding on the ground, and carried it back into the woods.”

But their most interesting sighting was this: “In mid-January about 8 p.m. a saw-whet owl spent a few minutes on top of a shepherd's crook, also working that vole colony in the snow.” Saw-whet owls seldom come to feeders, and it’s unclear how many migrate south from our area and how many stay the winter. These owls are really small. Males, for example, weigh about as much as an American robin, while females weigh only about 25% more.

Pileated Woodpecker Photos

Wil Conway visited a friend near Big Arbor Vitae Lake and shot fine photos through a patio door of two pileated woodpeckers. Note the differences between the male and female – the red crest on the male extends almost to its beak, and he has a red “moustache” on the side of his face.

Judy Ruch also sent me some good photos of a pileated at her feeders in Presque Isle. She noted, “When he hammers on the owl house, you can hear him from far away, the house acting as the perfect sounding board.”

Barred Owl Photos

Terry Mann in the town of Cassian sent me a photograph of a barred owl that came during the afternoon for three consecutive days to their feeders before moving along. There’s no discernible difference between genders, so it could have been a male or female. The good fortune they had in seeing it unfortunately has to be tempered by the fact that when nocturnal owls show up at people’s feeders during the day, it’s usually a sign of starvation. Let’s hope the owl caught what it needed and is back in the woods looking for prey at night like it was created to do.

Celestial Events

The new moon occurs on 2/18. On 2/25, after sunset look for Venus about three degrees below the moon. On 2/27, look at dusk for Jupiter about four degrees below the moon. We also reach 11 hours of daylight on 2/27.

Leap-day occurs on 2/29 because it takes the Earth about 365.25 days to orbit the sun. So every four years, we have to adjust our calendars accordingly.

Pine grosbeaks are finally filtering down from Canada into northern Wisconsin. First in our area to report them to us was Jo and John Knapp in Presque Isle who have been enjoying a flock of 14 to16 pine grosbeaks coming daily to their feeders since 1/17.

Audrae Kulas reported three female pine grosbeaks on 1/18. Jean Hall in Arbor Vitae observed her first pine grosbeaks on 1/20 as did Mary and I at our feeders in Manitowish. Pat Schwai on Cochran Lake saw her first pine grosbeaks, seven females and one male, on 1/21.

Several columns ago, I quoted Ontario ornithologist Ron Pittaway’s forecast for northern finches moving down into the U.S. this winter. He wrote, “A small movement of pine grosbeaks is probable because mountain-ash berry crops are variable and some are of poor quality in the boreal forest.” Indeed the movement has been small so far, but my hope is that everyone feeding birds in our area gets a chance to see one of these beautiful birds at their feeders. After all, those of us spending much of the family’s life savings on what have become semiprecious sunflower seeds deserve to be rewarded.

Non-Sighting

The summer tanager, affectionately nicknamed “Wrong-way” by those feeding him, has not been seen since 1/13. He was first seen on 11/17, so he survived nearly two months of a Northwoods winter, an exceptional feat for a bird which usually spends its winters in Central America. He may still be alive somewhere in the area – indeed, no one has found him frozen under a feeder – but the odds are certainly very long against his survival.

Two More Wintering Birds That Don’t Belong Here

On 1/23, Pat Schwai on Cochran Lake watched a grackle come to her birdbath for a drink. She noted that she had never seen one in winter. In the 19 years we’ve done the Christmas Bird Count in Manitowish Waters, we’ve found a grackle five times, which says they’re quite unusual, but not necessarily rare, to find during a Northwoods winter. Grackles are often the first migrant bird to arrive in spring – well, if you call mid-March “spring” – so they don’t winter too far away. Nevertheless, as a ground-feeding seedeater, they really don’t belong up here in snow country.

On 1/27, Jilleen Neumann in Hazelhurst e-mailed this: “I saw a big, fat robin yesterday about 4:30 P.M. hopping around on the snow under a mixed-seed bird feeder. Is this telling me we are having a mild winter?” Well, we are indeed having a mild winter overall, but I think the robin’s presence tells us more about either its great adventuring spirit or its need to see a therapist.

Northern Shrikes and Redpolls Arriving

Mary and I have still yet to see a northern shrike this winter, but others are now reporting a few. On 1/16, Jo and John Knapp in Presque Isle had a northern shrike hanging around for a few days, whereupon it left and then re-appeared on 1/27 for a day.On 1/23, Niki Childrey sent me a picture of a shrike near her home in Harshaw. On 1/25, Kathy Eder wrote: “We had a downy woodpecker feeding on our suet feeder and a shrike came down and chased her into the window. When she fell he swooped down. She tried to escape but he caught her and flew away with her. The woodpecker was almost as big as the shrike, and yet the shrike flew about 20 feet away where he finished the job and then when we tried to take a picture he flew way off into the woods, carrying the poor downy with absolutely no effort. It was pretty exciting.”

Common redpolls are finally arriving as well, becoming, well . . . rather common. Pat Schwai on Cochran Lake had 30 appear at her feeders on 1/12 when the northern counties were getting hit with heavy snow. On 1/21, John Eldredge in Sugar Camp reported having a flock of 25 to 30 redpolls at his niger seed feeder. Mary and I have maybe a dozen redpolls mixing in now with the swarm of goldfinches at our feeders. We still also have three American tree sparrows coming regularly, a species that doesn’t commonly winter this far north.

Evergreens, Ever Warm

Mary and I snowshoed or cross-country skied nearly every day in January with temperatures on those days varying from as high as 40°Fto as low as -25°F. The cold days reminded us of the importance of getting under conifer cover where the wind can be rocking up in the tree canopy but barely stirring a leaf on the ground.

Animals know this, of course. Mammals that survive a northern winter mastered the art of utilizing microclimates long ago. A moose can lower its heat loss by one-third by moving from an open meadow into a coniferous forest where reduced wind speed and radiant energy from the trees help keep it warm,.

Conifer cover not only reduces wind, it reduces the amount of snow that reaches the ground by two-thirds or more. One afternoon, we were snowshoeing in a foot of snow in an open wetland, and feeling very thankful for the snowshoes, and then we walked up into a dense pine stand where there was only three inches of snow on the ground, making our snowshoes more of a hindrance than a help.

Again, animals know all about these variations in snow depth and snow character. Coyotes, for instance, possess relatively small feet, and their success or demise is keenly related to their ability to negotiate different types of snow. Soft snow is their enemy. Veteran tracker Jim Halfpenny in Yellowstone Park writes, “I can tell from their [coyote] footprints that they walk carefully on soft snow (trying to avoid sinking in too deep), trot on medium snow (but lightly, to avoid breaking through thin crusts), and lope on hard snow crusts. Coyotes often follow wind-packed courses on the leeward side of exposed sagebrush avoiding careless steps to the side where the snow is soft.” If you’ve ever “post-holed” up to your knees in deep snow, you know exactly how exhausting that can be. In winter, the energy balance for coyotes gets tipped profoundly into the red when the snow is deep and soft.

Soft, deep snow is nirvana, however, for wintering rodents who use the snow cover as a thermal blanket. Mice and voles tunnel under the snow, often constructing grass nests at the end of the tunnels where they huddle for warmth. Halfpenny calculates on a calm 23 degrees F night, a mouse would lose 3.7 times more energy per minute on the snow surface than in its tunnel.Halfpenny noticed that many more tunnel shafts appeared above the snow after very cold nights. So, he implanted a radio-transmitting thermometer into a deer mouse, then set it loose at 3 A.M. with the temperature at -30F. The mouse ran for several minutes across the snow, and their radio signal indicated its body temperature was dropping precipitously. The mouse quickly dug a tunnel, waited twenty minutes until its temperature normalized, then took off across the snow again. The mouse did this three times, its internal body temperature dropping as much as 20 degrees when it ventured out.

Every animal constantly adapts to changing winter conditions and has its own ingenious story of winter survival. The moose mentioned earlier actually overheat on sunny winter days, and must move to north-facing slopes to cool off, while elk, with a smaller body mass and less insulation, hang out on the south-facing slopes to absorb all the sun they can get.

Trying to understand all of their stories and how they interact helps keep me warm all winter, too.

Celestial Events

Here’s what to look for when planet-watching in February: At dusk, the action is all in the southwest – look for Venus, brilliant at -4.1 magnitude, in the southwest, and for Jupiter, not quite as bright at -2.3 magnitude, high in the southwest. Before dawn, look for Mars (-0.8 magnitude) high in the south, and for Saturn (-0.5) also in the south.

Saturday, February 4th, marks the midway point between winter solstice and spring equinox, while February 5th marks the midway point between the 35-year average ice-up and ice-out dates on Foster Lake in Hazelhurst. We also receive 10 hours of sunlight as of 2/7. So, for those getting a bit winter weary, we’re getting there.

The full moon (the “snow/hunger/when coyotes are frightened moon”) also occurs on 2/7. The Ojibwe name for February is onabinigizis, meaning “snow-crusted month,” referring to the typical thaw we get in later February that forms a crust on top of the snow.